rational analysis and fell outside the scope of “science,” or “knowledge of the necessary and universal”. While it revealed the forms or natures of things to sense, it remained itself impervious to intellect, which grasped these natures and rendered them intelligible only by divesting them of matter, by abstracting them from matter. Reality is intelligible only in so far forth as it is immaterial, either in fact or by abstraction. The human intellect, being itself spiritual, is “receptive of forms without matter”. But being itself allied with matter, its proper object is none other than the natures or essences of corporeal things, abstracted, however, from the matter in which they are actually “immersed”. The only reason, therefore, why any intelligible form or essence which, as abstract and universal, is “one” for intellect, is nevertheless actually or potentially “manifold” in its reality, is because it is allied with a material principle. It is the latter that accounts for the numerical multiplication, in actual reality, of any intelligible form or essence. If the latter is material it can be actualized only by indefinitely repeated, numerically or materially distinct, alliances with matter. It cannot be actualized “_tota simul_,” or “once for all,” as it were. It is, therefore, the material principle that not merely reveals, but also constitutes, the individuation of such corporeal forms or essences. Hence, too, the individual as such cannot be adequately apprehended by intellect; for all intelligible principles of reality are formal, whereas the individuating principle is material. On the other hand, if an intelligible essence or form be purely spiritual, wholly unrelated to any indeterminate, material principle, it must be “one” not alone conceptually or logically but also really: it can exist only as “one”: it is of itself individual: it can be differentiated from other spiritual essences not materially but only formally, or, in other words, not numerically but by a distinction which is at once individual and specific. Two pure spirits cannot be “two” numerically and “one” specifically, two for sense and one for intellect, as two men are: if they are distinct at all they must be distinct for intellect, _i.e._ they cannot be properly conceived as two members of the same species.